Control apparatus for internalcombustion engines



March 9, 1 ME. CHANDLER CONTROL APPARATUS FOR INTERNAL-COMBUSTIONENGINES Filed Feb. 27, 1946 3 Sheets-Sheet 1 INVENTOR. S MZTO/VE flaw/wiE W AGENT March 9, 1948. M. E. CHANDLER 2,437,377

I CONTROL APPARATUS FOR INTERNAL-COMBUSTION ENGINES Filed Feb. 27, 19463 Sheets-Sheet 2 TO INCREASE v PUMP DELIVERY I60 "I"? To I N (R EASEPUMP oeuvsm' p g IIIIIIIIIIIII A March 9, 1948.

M. E. CHANDLER 2,437,377 CONTROL APPARATUS FOR INTERNAL-COMBUSTION.ENGINES Filed Feb. 27, 1946 3 Sheets-Sheet 3 FUEL SUPPLY SYSTEM SEEFIG.1

HYDRAULIC MOTOR SEE FIGJ.

INVENTOR MILTON E.,,OHANDLER AGENT,

- chambers, or directly into the intak Patented Mar. 9,1943

s PATENT; OFFICE of New Jersey Application February 27, 194 Serial No.650,624

, y s Claims. (01.123-140) 'The present invention relatesto apparatusfor controlling fuel supply to internal combustion engines;andparticularl'y to the general type of fuel supply systems in whichfuel, unmixed with air, is injected directly into-the engine combustionV i emanifold just outside the cylinder intake ports, 7 i

The type system referred to usually employs a set of injectionpumps, onefor each cylinder, and. means are provided for simultaneous control ofthe capacity per stroke of all pumpsin order to regulate both total-fuelflow andthequantity of fuel delivered to each combustion chamber.

' An essential requirement of such a system is that fuel flow may beproportional to air flow under all conditions of operation.Some meanswhich eifectively measures the airflow is therefore commonly provided tocontrol the injection pump delivery and thereby the fuelflow; In orderto stop an enginefpr'ovided with such a system, it is desirable toover-ride the normal con-, trol so as to set the injection pump deliverycontrol at its minimum or zero position.

An object of the present invention is to provide an improved system ofthe character'described wherein a fuel meter is made to control ahydraulic motor by means of a servo-valve inter mediately disposedtherebetween, in proportion to air flow or as otherwise determined bythe fuel meter tosatisfy peculiar requirements of theengine. A V

Additional objects are to provide a simplified form of fuel meter. forthe purpose stated, and to provide a system in whichenginespeed and loadchanges have a minimum effect on the accuracy of fuel metering. r

A further object is tolprovide 'anfover-ride mechanism operable torender the servo-motor unresponsive to motor. fluid pressure, therebyallowing the injection pumps to be set for minimum orzero delivery. 'i J1 Other objects and advantages-ofthe present invention will becomeapparent from a consideration of the; appended specification, claims anddrawings, in which Figure 1 illustrates, somewhat diagrammatically, afuel supply system for an internal combustion engine foraircraftembodying the principles of my invention; o

Figure 2 shows a cross-sectional view of a hy draulic motor and aby-pass valve therefor built in accordance with principles of myinvention;

,Figure 3 shows a cross-sectional view of the by-pass valve referred to,taken on the line 3-3 of Figure 2 and looking in the direction of thearrows;

Figure 4vshows a cross-sectional view of the bypass valve rotated 90from the position shown in Figure3; A V

. Figure 5 shows, somewhat diagrammatically, a

modified form of fuel meter which may be used in the system of Figure 1;

Figure 6 illustratesa cross-sectional View of a common type of injectionpump nozzle assems bled into an engine combustion chamber, andasimilarly conventional injection pump connected therewith; and f Figure7 illustrates, somewhat diagrammatically, means for operating the motorby-pass valve by movement of the mixture control of Figure 1.

Reference characters designating the pressures existing in the variousunits, which are shown on the drawing (in parentheses) where applicable,are itemized as follows for reference purposes:

p0, air pressure at impact tubes p, air pressure at Venturi throat p1,regulated air pressure at fuel meter 7 ran-p, venturi air pressuredifferential 100-101, mass air flow metering pressure differential pr,inlet fuel pressure from fuel pump pr, regulated fuel pressure (atupstream side of metering restrictions) pd, discharge fuel pressure (atdownstream side of metering restrictions)l pa, motor fluid supplypressure; maximum (=pd asshown ondrawing) j pt, motor fluidsupplypressure; minimum pm, motor pressure differential component;maxipipd, fuel pressure differential, acrossmetering jetsystem n; qpmeps, motor-pressuredifferential L 1 I Figure 1 I Referring to thedrawing, there is shown a body ID of a carburetor for an internalcombustion engine, the interior of"whichserves as a conduit for all airdelivered into theengine. Air enters atan inlet l2'; and flows thru ametering venturi l4 and a passagelfi, past a throttle 20 to an outlet24. A supercharger may be used upstream from inlet I 2, or downstreamfrom outlet 22;; or a combinationof superchargers so located maybe'employed.

I Pressure head at the'throat of venturi I4 is rendered measurable byprovision of ports I5 leading to interconnected channels IS, the numberof ports l5 and their location being such aswill permit an-accuratemeasure of static pressure p at entrance to ports [5. j

Total head at the inlet I2 is rendered measurable by provision of impacttubes '26 leading to interconnected channels 28, the number and locationof impact tubes 26 being such that a satisfactory traverse of theairstream is obtained at the outer ends of" tubes 26, which are open toreceive impact pressure of the entering air.

The Venturi air pressure differential, Po-P,

varies substantially in accordancewith the square of the velocity ofair' flowing thru the venturi;

In order to obtain a gravimetric measure of;

airflow, an amount, of air sufiiciently small to pre;

vent air metering deficiency is allows to fi QW' from inlet i2 intoimpact tubes 26, thru conduits ing direction.

28 and 32 into a chamber ,3; f a fuel meter generally indicated at 36,tl llfl l a restriction 38 into a chamber 40 in fuel meter'35,outofchains ber 40, thru a conduit 42, past a valve 44 and into a chamber 46;thence into conduits 4 3, 1,6 and 15.

to the throat of venturi I4; 1. e. from pressure 120 to pressure 17, viathe path defined. j The valve 44 is operated by a bellows 50, one endofwhich is h red in chamber 4.6. Bellows B is made responsive 'tote'm pture changes by enclosure therein of a suitable temperature resp r s vesas r a q b r s a w re bellows 50also vbecomes pressure responsive. Pressure and temperature in chamber 46 ,are the ,same as pressure at theVenturi throat; a rath rerqre, movement of valve 54 isa functiohl'pf airdensity changes at theVenturi throat.

Valve 44 moves toward open position as the air density inchamber 46increases, and toward closed position .aS the air density decreases. 'Asthe volume rate of flowjof a given constant mass air flow increasesvowing to jadecreasefof air den sity, the Venturi pressure differential,po jb, increases and the componentrpressure drop p1--p, across valve 44increases; but valve 44 moves to ward closed position sufiiciently torestrict flow past the valve theiamount required tomaintain asubstantially constant .value of component drop, ply-p1, acrossrestriction 38 and thereby across diaphragm .58 which separates chambers34 and 4D.

A lesser amount of movement than is required for density compensation.is imparted to the valve as a result of changes in mass -air flow ofconstant density, but it is nevertheless possible to contour valve 44 sothat the massair-flow metering pressure differential,- .pwpi, is anacceptable measure of mass air flow at all values of air flow.

Fuel at superatmospheric pressure, supplied to the carburetor by a fuelpump or othermeans, enters conduit 52' which carries it td a 'fuel inletvalve 54 in fuel meter Brincipal elements in the course of flow frominlet valve 54 are, suciv l a ii chambers c ndu .4; u ly en r ed-m x recame a l t Sysn 18 n in a chamber .5 nd a on i 12 which carries the fueldirectlyv to a set of in,- jection pumps, one of which is shown inFigure 4, thence to the spray nozg'les' also as shown in Figure 4' r l.j

In fuel meter 36, a diaphragm $2 separates chamber 40 from chamberffiiiin'which the fuel pressure is the same as that bn the upstream side ofjet system "It; and is designated pl: a like diaphragm 66 separateschamber from a chain ber 58 in which the fuel pressure is the same s ton he o n tre m ide for et ste 1.18; and is designated pa. "The: fuelinletvalye .54 is subject to controllingforces as'followsfthe' forceproduced by the mas's'a'ir me eri g prVessure differential,pQ-p1',"acting 'aae a ara in 58, tends'to open the valve; the forceproduced by fuel pressure pd, acting on diaphragm 65, tends to open thevalve and the force produced by fuel pressure pr, acting on diaphragm62, 1 tends to;

close the valve, so that the net iorce produced y the fuel pressuredifiercnt al perm. actin n diap a m Bl r nfifite ds to clcscthe valve;

reacting on diaphragms 62 and 66 in a closing,slireciiqnplwngiinultaneous occurrence of these renditions iingletyalve54 is actuated to a position of equilibrium in-which the opposedcontrolling forces'are equal or in which the force proportional tomassair flow equals the force proportionalto fuel'flow, in consequence ofwhich fuel flow is Proportional to air flow.

Jet system 18 comprises fixed area restrictions 9 a 3 sedan-praise 5control ed by a nf e 'su -i s e se is g eat a ve at b as d to esd n s byspri g at Mixt r central valve TIM hW t full line i its lsn rei i w ch'al w iu i0 a ow tum con u t 8. into chamber 159 thru jet 99 into chamber9|. Rotation of valve: 102 to the dotted line or rich' posl'tionlperniits fuel to fl ow thru conduit '0" and le ut 'l fiamher th nceth u i 93andinto .chamberllli.

From chamber 9-], all fuel entersan orifice lu l w c is e v to met r hiue wh n h e a v 6 iim a la e-q fle "ll r sp nse to m m n o hre'it evelvet"! lever 12. in 23, and lever 15, ltaly'e 196 is effective withina r her Pa e? 9 throttl me em nt m c d ra le 9 rest-throt le p sitione hihrgtll Pas es out f that an e of m vement, th l l 1.0.5 ,5 FQFWQFQQQSQhat t e ess r res r ct the. r ew 9 i is the eswintion wa far, it isshown tha the fuel isrneasured as a function of the fuel pressureerential rim-n1 Which is,.control1ed by fuel meter 3.6,. T ma e such.control possible however, it is necessary to maintain the low pressurecomponentps ,of the 1 .81 pressurediffer? ential within a range ofvalues that will always be less than the minimum value of inlet pressurepr by an amount slightly greater than maximum pressure loss occurringbetween conduits 52 and 12. A motor pressure regulator 84, incooperation with the motor shown in Figure 2, controls dischargepressure pa. Elements of regulator 84 include: a chamber l0] connected b.a conduit H15 toconduit 32 at impact pressure a chamber I09 suppliedwith fuel at pressurepd through a conduit 65; and a diaphragm I08,separating chambers I01 and U19, attached to a valve 8-2, the position"of which is determined by the force on diaphragm I08 due to theregulator pressure differential pdpo and by an opposing force due tospring [0.

In a condition of equilibrium, pressure pa has a predetermined value andvalve 82 closes entrances to channels 86 and 88 which converge into asingle conduit 63 which. is connected to a oham- The position. of pistonI l i. is. determined by the equilibrium of forces due to the motorpressure differential phi-pl and. a spring H6 whichbiases the piston illfor movement in a. downward direction, as it appears in Figure 2.Wheneverunbalance ofrthese force voccurs, piston rod HZ piston 'IHupwardly, thereby causing actuation of pump delivery regulating means toincrease pump delivery. As pump delivery increases, the pressure pa inconduits .I2 and 65 and in chamber I09. decreases. until thepredetermined value of pd-.-po is restored. j

Similarly, when pressure differential pd-.-po at regulator 84, Figure.1,;tends.;to :drop below the predetermined setting value, valve 82 movesin cooperation with spring H0, opens a'valve portbetween conduit 86 andchamber 83, thereby allowing fuel tofiow from motor chamber I I4, intoconduit 63 to conduit 86,.into chamber 83 to conduit 51. .The pressurepit-in chamber H4 is thus equalized with that in chamber I I5 and thespring I I6 then moves the piston I II downwardly, operating the pumpdelivery regulating means todecrease pump delivery. .This increasespressurepa and pump. delivery. continues todecrease until the pressuredifierential pd-po increases, to the predetermined value. o y

In Figure 1, fuel is used as the motor fluid; oil or other fluid atsuitably high pressure may be employed equally well with slightmodification of regulator valve 82. Other equivalent forms. of.servo-motors and control valves therefor may also be used. 7 p

In order that the injection pumps may be im mediately operated tominimum delivery position,

the by-pass valve I I1, Figure 2, is provided. Valve- I I1 is operableby a lever I2I to a position shown in Figure 4 which permits motor fluidto flow from chamber H4 thru conduits H9, H8, and I20,into chamber II 5.-In that position, valve H'I also blocks the conduits 63 and 61, so thatpressure pa in chamber H4 equals pressure pt 7 in chamber I I5 and themotor is made solely responsive to a spring I I6 which moves thepumpdelivery control to minimum delivery position. When leverqIZI operatesvalve III into a position in whichentrance toconduit H9 is blocked, asshown 1 in Figure 3, chambers I I4 and I I5 are not connected and themotor pressure differential is. controlled by regulator valve 82, Figure1.

Valve H1 is linked to the valve I in Figure 7, so that valve H1 isnormally posi tioned as illustrated in Figure 3 when the mixture,control valve is in either lean or-rich positions shown by solid anddotted lines respectively in Figure 1. When valve I02 is moved from leanposition in a clockwise direction, by means of a mixture control lever85 attached to shaft I03, valve H1 is operated to full by-pass andcutoff position (Figure 4) by the arrangementshown in Figure 7, in whicha cam 81 fixed to shaft I03 engages one end of a lever 89 having a fixedpivot 8|, a link 'I'I connecting the other end of lever 89 with lever I2I. A spring II holds lever 89 against a stop 13 when the mixture controlvalve is in ilean-or rich or intermediatepositlons.

On stopping the engine,the mixture control lever 85 is movedcounterclockwise to an extreme position at which lever 2I.moves valveII'I into the 11.11 byma nd cu -01 pos t onp l ie r ik as shown;

The motor piston m immediately starts moving togminimum deliveryposition and the engine is' thus quicklycutofi from its fuel supply. Asthey engine decelerates, the air flow decreases and the pressurepd inchamber I09, Figure 1, decreases.- This pressure decrease, however, lagsbehind fuel pump delivery decrease'and, because the mixture controlvalve remains open when cut-off occurs at y-p ss V v Ill, fuel isconstantly supplied to conduit I2 and to the injection pumps at apressure which prevents accumulation of vapor upstream from theinjection pumps. On starting theengine, therefore, initial charges offuel unmixed with vapor are obtained and one source of difficultstarting is thereby eliminated.

Figure 5 7 Referring to the drawing, there is shown a modified form offuel meter, generally indicated as I20, usable in the system of Figure 1and essentially thesame as fuel meter 36 of Figure l, except foromission of diaphragm 66, chamber 68, and conduit I0. Elements common toboth fuel meters 30 and I26 are designated identically.

Fuel at superatmospheric pressure, supplied to the carburetor by a fuelpump or other means, enters conduit 52 which carries it to a fuel inletvalve 54 whence it flows past valve 54 to a chamber 64 and into aconduit I4 from which the further course of flow is the same as forFigure 1.

In fuel meter I26, a diaphragm 62 having a fixed connection with valve54 separates chamber 40 from chamber 64, in which the fuel pres.- sureis the same as that on the upstream side of jet system I8, Figure l, andis designated pr. Chamber 40 is separated from a chamber I22 by a seconddiaphragm 58 which also operates in contact with valve 54. Chambers I22and 40 are connected thru restriction 38 and are respectively maintainedat pressures po and 01 by means of conduits 32 and 34, as has beendescribed in connection with Figure 1.

The fuel inlet valve 54 is subject to controlling forces as follows: theforce produced by the mass air metering pressure differential po-pi,acting on diaphragm 50, and tending to open the valve; and by theopposing force produced by the pressure differential p1-p1, acting ondiaphragm B2 and tending to close the valve, A spring I24 biases thevalve 54 toward an open position with another force equal to thatobtainable by means of a diaphragmlike diaphragm 62 subjected topressure differential lid-29o, established by the motorpressureregulator 84 of Figure 1.

At any constant value of mass air flow, valve 54 is subjected to adownward force due to the mass air metering diiferentia po-p1, acting ondiaphragm 62 plus the above specified fixed load on spring I24, thetotal of those two forces bein equivalent to a force produced by thefuel pressure pr acting upwardly on diaphragm 62.

Similarly, for any condition of constant jet area in jet system I8 thefuel pressure differential pP-po is a measure of fuel flow; whence, uponsimultaneous occurrence of these conditions (constant mass air flow andconstant jet area), inlet valve 54 is actuated to a position ofequilibrium in which a force proportional to mass air flow equals aforce proportional to fuel flow, in consequence of which fuel flow isproportional to air flow. The spring I24 may be adjusted to provide aslightly greater load than that specified, in order to increase fuelflow in a range of air flow in which the difierential pop1 does notsatisfy usual requirements,

It is; readily apparent that simplification; of the fuel'meter as shownin Figureis mad'e possible only by virtue of the. function of themotorpressure regulator 84', Figure I, the associatedmotor, Figure 2, and thefuel injection pump, Figure 6. These associated elements: maintain aoonstant value of differential p 1po; i. e., at a constant Value ofpressure no, the motor pressure regulator 84 maintains, a constantpressure pa on the downstream side of jet system I8 by controlling themotor, Figure 2, in a manner which permits the latter to set theinjection pump delivery to take away all fuel flowing from thejets atthe predetermined constant value of pressure m. The injection pumpdelivery is therefore, in effect, controlled in response to air flowthru the carburetor,

Figure 6 Referring to the drawing, there is shown one of the injectionpump-s I40 of conventional type,

it being understood that there is a plurality of I such pumpscorresponding to the number of cylinders I 12 of the engine. The pumpI40 has a hollow outer body I i' lto which fuel is supplied thru abranch of the fuel conduit I2.

Positioned Within the outer body I44 is an inner body MB having portsIABand I50 connecting a chamber in the outer body with a central bore orcylinder in the inner body. The bore in the inner body I46 isopen at thebottom and communicates With a conduit I52 which in turn communicatesthru a self-closing ball check valve I5 1 with a conduit I55 leadingdirectly into the motor cylinder I132. Mounted in the central' bore forboth longitudinal and rotative movement is a plunger I58 carrying, atits projecting upper end, the before-mentioned gear I30 meshing with therack I28. The plunger I58 is reciprocated by a cam I60 on a shaft I62driven by the engine.

When the engine is in operation the shaft I62, with the several cams I50thereon, is operated to move the plunger I58 of each injector pumpdownward so as to deliver a charge of fuel to the engine cylinder at aproper time inrelation to the cycle of the engine piston. The plungerI58 has a contoured recess 16 formed therein which providescommunication between the ports I48 and I50 and the cylinder ahead ofplunger I58, The point in the travel of plunger I58 at which pumpingstarts is determined by the angular position of the plunger, whichdetermined" the point at which port I48-is closed by the helicallycontoured portion of recess I64 The plunger I58 is rotated by the rackI28 and the gear I30 thru the action of the servo-motor as alreadydescribed. When theservo or fluid motorits lowermost position the chargeof" fuel injected into the cylinder is at the maximum. The point in thestroke of plunger I58 at which pumping terminates is always the same,being established by. the uncovering of port. I50 by the annular grooveI65 which communicates thru recess I64 with the cylinder ahead ofplungerll'rfl.

The terms andv expressions which Ihave employed are used as terms ofdescription and not of limitation, and I have no intention, in the useof. such" terms and expressions, of excluding any equivalents of thefeatures shown and described or portions thereof, but recognize that.various modifications are possible within the scope of theinventionclaimed.

I claim as my invention:

1, A fuel supply system for an internal combustion engine, comprising afirst conduit for air flowing into said engine for combustion urposes,means in said; first conduit effective to produce an air pressuredifferential, that is a" measure of the air flow; a second conduit forfuel flowing into said engine, a metering orifice in said sec.- ondconduit, the fuel pressure differential across saidlorifice: being ameasure of the. fuel flow therethru, and a fuel meter responsive to saidair pressure differential efiective to vary said fuel pressuredifferential whereby said fuel flow is proportional to said airflow; aninjector pump mechanism for delivering fuel to said engine, means insaid mechanism to vary the rate of said fuel delivery, apassage for flowof fuel discharged fromsaid metering orifice to said injector pumpmechanism, and hydraulic motor means for positioning said deliveryvarying means; means for controlling said motor means including a valvehaving a normal position in which said motor means is stationary andeffective upon opposite movements from said normal position to causeoperation of said motor means in opposite directions, and meansresponsive to the metering orifice I discharge pressure for operatingsaid valve.

2. A fuel supply system for an internal combustion engine, comprising afirst conduit for air flowing into saidengine for combustion purposes,means in said first conduit effective to produce an air pressure.differential that is a measure of the air flow; a second conduit forfuel flowin into saidengine, a metering orifice in said second conduit,the fuel pressurediiferential across said orifice being a measure of thefuel flow therethru, and afuel meter responsive to said air pressuredifferential effective to vary said fuel pressure differential wherebysaid fuel flow is proportional to said airflow; an injector pumpmechanism for delivering fuel to said engine, means insaid mechanism tovary the rate of said fuel delivery, a passage for flow of'fueldischarged from said metering orifice to'sald injector pump mechanism,and hydraulic motor means for positioning said delivery varying means;means for controlling said motor means including a valve having a normalposition in which said motor means is" stationary and effective uponopposite movements from said normal position to cause operation of saidmotor means in opposite directions, means responsive to the meteringorifice discharge pressure for operating said valve, and spring meansbiasing said pressure responsive means opposition to said meteringorifice discharge-pressure.

3-. A fuelsupplysystemfor an internal combus-- -thru; and a fuel meterresponsive tosaid air 9 pressure differential effective to vary saidfuel pressure differential whereby said fuel flow is proportional tosaid air flow; an injector pump mechanism for delivering fuel to saidengine, means in said mechanism to vary the rate of said fuel delivery,a passage for flow of fuel discharged from said metering orifice to saidinjector pump mechanism, and hydraulic motor means for positioning saiddelivery varying means; means for controlling said motor means includinga valve havinga normal. position in which said motor means is stationaryand effective upon opposite movements from said normal position to causeoperation of said motor means in opposite directions, means foroperating said valve responsive to .a control pressure differentialbetween the metering orifice discharge pressure and an air pressuresubstantially equal to atmospheric pressure, and spring means biasingsaid pressure responsive means in opposition to said control pressuredifferential; said pressure responsive means, said spring, said valveand said delivery varying means being effective to maintain said secondpressure differential at a substantially constant predetermined value. i

4. A fuel supply system for an internal combustion engine, comprising afirst conduit for air flowing into said engine for combustion purposes,means in said first conduit effective to produce an air pressuredifferentialthat is a measure of the air flow; a second conduit for fuelflowing into said engine, a metering orifice in said sec- 0nd conduit,the fuel pressure differential across 4 said orifice being a measure ofthe fuel flow therethru, and a fuel meter responsive to said airpressure differential effective to vary the' fuel pressure upstream fromsaid metering orifice; an injector pump mechanism for delivering fuel tosaid engine, means in said mechanism to vary the rate of said fueldelivery, .a passage for flow of fuel discharged from said meteringorifice to said injector pump mechanism, and hydraulic motor means forpositioning said delivery varying means; means for controlling saidmotor means including a valve having a normal position in which saidmotor means is stationary and effective upon opposite movements fromsaid normal position to cause operation of said motor means in oppositedirections, means for operating said valve responsive to a, secondpressure differential between the metering orifice discharge pressureand an air pressure substantially equal to atmospheric pressure, andspring means biasing said pressure responsive means in opposition'tosaid second pressure differential; said pressure responsive means, saidspring, said valve and said delivery varying means being effective tomaintain saidsecond pressure differential at a substantially-constantpredetermined value, whereby said fuel meter is effective to va y saidfuel fiow in proportion to said air flow.

5. A fuel supply system for an internal combustion engine, comprisin afirst conduit for air flowing into said engine for combustion purposes,means in said first conduit effective to produce an air pressuredifferential that is a measure of the air fiow; a second conduit forfuel flowing into said engine, a metering orifice in said secondconduit,the fuel pressure differential across said orifice being a measure ofthe fuel fiow therethru, and a fuel meter responsive to said airpressure differential and said fuel pressure differential for varyingsaid fuel fiow proportionally to said'air: flow; an injector pumpmechanism for delivering fuel to said engine, means in said mechanism tovary the rate of said fuel delivery, a passage for flow of fueldischarged from said metering orifice to said injector pump mechanism,and hydraulic motor means for positioning said delivery varying means;means for controlling said motor means including a valve having a normalposition'in which said motor means is stationary and effective uponopposite movements from said normal position to cause operation of saidmotor means in opposite directions, means responsive to the meteringorifice discharge pressure for operating said valve, and spring meansbiasing said pressure responsive means in opposition to said meteringorifice discharge pressure.

6. A fuel supply system for an intern-a1 combustion engine, comprising afirst conduit for air flowing into said engine for combustion purposes,means in said first conduit effective topro duce an air pressuredifferential that is a measure of the air flow; asecond conduit'for fuelflowing into said engine, a metering orifice in said second conduit, thefuel pressure differential across said orifice being a measure of thefuel fiow therethru, and a fuel meter responsive to said air pressuredifferential and to the fuel pressureupstream from said metering orificeeffective to vary said fuel pressure differential whereby said fuel flowis proportional to said air fiow; an injector pump mechanism fordelivering fuel to said engine, means in said mechanism to vary therateof said fuel delivery, a passage for fiow of fuel discharged from-saidmetering orifice to said injector pump mechanism, and hydraulic motormeans for positioning said delivery varying means; means for controllingsaid motor means including a valve having a normal position in whichsaid motor means is stationary and effective upon opposite movementsfrom said normal position to cause operation of said motor means inopposite directions, means responsive to the metering orifice dischargepressure for operating said valve, and spring means biasing saidpressure responsive means in opposition to said metering orificedischarge pressure. r

7. A fuel supply system for an internal combustionengine, comprising afirst conduit for air flowing into said engine for combustion purposes,means in said first conduit effective to produce an air pressuredifferential that is a measure of the airflow; a second conduit for fuelflowing into said engine, a metering orifice in said second conduit, thefuel pressure differential across said orifice being a measure of thefuel fiow therethru, and a fuel meter responsive to said air pressuredifferential and to the fuel pressure upstream from said meteringorifice effective, to vary said upstream pressure; an injector pumpmechanism for delivering fuel to said engine, means in said mechanism tovary the rate of said fuel delivery, a passage for flow of fueldischarged from said metering orifice to said injector pump mechanism,and hydraulic motor means for positioning said delivery varying means;means for controlling said motor means including a valve having a normalposition in which said motor means is stationary and effective uponopposite movements from said normal position to cause operation of saidmotor means in opposite directions, means for operating said valveresponsive to a second pressure differential between the meteringorifice discharge pressure and an air pressure substantially equal toatmospheric pressure, and spring means biasing said pressure responsivemeans in opposition to said 11 second pressure differential; aidnressureresponsive means, said spring, said valve and said delivery varyingmeans being effective to main tain said second pressure differential ata sub stantially constant predetermined value, whence said fuel flow isproportional to said air flow,

'8. A fuel supply system for an internal cornbustion engine, comprisinga first conduit :for air flowing into said engine for combustionpurposes, means in said first conduit effective to produce an airpressure difierential that is a measure of the air flow; a second onduitfor fuel flowing into said engine, a metering orifice in said secondconduit, the fuel pressure differential across said orifice bein ameasure oi the fuel flow the-rethr-u, and a, 'fuel meter responsive tosaid air pressure differential effective to vary-said :fuel pressurediiierential whereby said fuel fiow is proportional to said air flow; aninjector pump mechanism for delivering fuel to said engine, means insaid mechanismto vary the rate of said fuel delivery, ;a passagefortfiow of fueldisclrarged from said metering orifice to said injectorpump mechanism, and hydraulic motor means for positioning said deliveryvarying means in re, sponse to a motor pressure differential suppliedthereto; means controlling the motor pressure difierential in saidhydraulic motor means by reg ulating at least one component pressure ofsaid motor pressure differential thereby controlling said hydraulicmotor means, said means controlling said motor pressure -difierentialincluding a valve having a normal position in which-said moe tor meansis stationaryand efiective upon opposite movements i-rom said normalposition to cause operation of said motor means in opposite directions,and means responsive to the metering orifice discharge pressureforOperatingsaid valve.

9. A fuel supply system for an internal combustion engine, comprising afirst conduit for-air flowing into said engine forcornbustlon purposes,means in said first conduit effectiveto. pr duce an air pressuredifferential that is a measure of the air fiow; a second conduit for,fuel flowing into said engine, a metering orifice in said s e e-. ndconduit, the fuel pressure differential across said orifice being ameasure of the vfuel flow therethru, and a fuel meter responsive to saidair pressure differential effective to vary said fuel pressurediiierential whereby said fuel flow is proportional to said air-flow; aninjector pump mechanism for delivering ,fuel to said engine, means insaid mechanism to vary the rate of said fuel delivery, a passage forflow offuel .dis charged from said metering orifice to said injecs. torpump mechanism, hydraulic motor means for positioning said deliveryvarying means in re-. sponse to a motor pressure difierential appliedthereto, and spring means biasing said motor means ,for movement in ,adelivery decreasing direction; first means for controlling said motormeans including a valve having a normal posh tion in whichsaid motormeans is stationary and effective upon opposite movementsfrom said nor.-mal osition to cause operation of said motor means in oppositedirections, and means resno sive to the metering orificedischa igepressure 7 operating said valve; and second means for o n: trolling saidmotor means, said second means comprising a motor by-Pass valveand means9 Operating said .by-pass valve between a first po: sition in which .itby-PaSSeS said motor meansand a second position in which said motormeans is controlled by said first motor ,controlmeans, alone, said.motor by-pass valve being v,eiiective to yen:-

der said first means inefiective by reducin Said :motor pressure:difierential to zero value, thereby allowing said sprin means toposition said fuel delivery varying means for minimum delivery f om s dinjection pumps.

10. Valve mechanism for selectively connecting one' pair of fluidconduits to a second pair of conduits or to each other, com-prising acylinder, a piston rotatable insaid cylinder, said piston having aninternal passage extending longitudinally thereof, each end of aidpassage terminating in one of :a pair of generally radial passagesextending from said internal passage to spaced ports on the exterior ofsaid piston, said piston having a pair of recesses'in its peripheralsurface located substantially diametrically opposite said ports andextending circumferentially of said piston for less than half of theperiphery thereof, said cylinder having a first pair of ports spacedangular-1y and longitudinally the same as said piston ports and leadingto said one pair of conduits so as to connect said conduits with eachther t ru said internal pa s ge when said piston is in afirst positionwherein said piston ports arealien d wi hsaid first p ir of. cylinder psaid cylinder also having a second pair of ports leading to said secondpair of conduits and located substantially diametrically opposite saidfirst pair of cylinder ports, so that each of said first pair of portsis connected thru its associated recess in said piston with one of saidsecond pair of ports, and said piston ports are blocked by the cylinderwalls when said valve is rotated to a second position substantiallyninety degrees from said first position, and means for rotating saidpiston.

1-1. Hydraulic control apparatus, comprising a fluid m tor havin :a-p rf responsibl ham ers separated by :a m ab e, all, .a first pa r of fluidsupply conduits connected respectively to said pair oi-chambers; control"means for said motor including a sourc of, motive fluid under w sure, adrain conduit, a-second pair or fluid conduits a first control val :fosele ve y o ting one of said second pair of conduits to said source orto saiddrain conduit, and a second control valve for selectivelyconnecting said first pai Of fluid conduits to said second pair ofc0nduits or to each other, said second valve coniprising a cylinder, apiston rotatable in said cylinder, said piston having an internalpassage extending longitudinally thereof, each end of said passageterminating in one of a pair of generally radial passagesextending fromsaid internal passage to spaced ports on the exterior of said piston,said piston having a pair of recesses in its peripheral surface locatedsubstantially diametrically opposite said ports and extendingcircurnierentially of said piston for less than half or the peripherythereof, said cylinder having a first pair of ports spaced angularly andlongitudinally the sameas sa d piston po ts, and le ding t sa d. on pa rof condu ts s s to co e t Said conduits withleach other t-hru saidinternal pass g when said piston isa f r pos o e in said piston portsare aligned with said first pa r of. oyl nder ports, said yl nder a havialseoond pair of ports leading to said second pair o conduits a dlocated substantia ly d am itally opposite said first pair of cylinderports, so that each of said first pair of ports is connected t rui s asocia ed r cess in said pis n wi h on otsaid second pair of ports andsaid piston ports are blocked by the cylinder walls when said valveisrctateclto a second pos ion su stantia y ni e y degrees from saidfirst position, and means for rotating said piston, said second valvebeing effective in said first position to place said first valve incontrol of said motor and in said second position to terminate controlof said motor by said first valve.

12. Hydraulic control apparatus, comprising a fluid motor having a pairof 'expansible chambers separated by a movable wall, a spring biasingsaid wall in a direction to collapse one of said chambers, a first pairof fluid supply conduits con' nected respectively to saidpair ofchambers; control means for said motor including a source of motivefluid under pressure, a drain conduit, a second pair of fluid conduits,a first control valve for selectively connecting one of said second pairof conduits to said source or to said drain conduit, and a secondcontrol valve for selectively connecting said first pair offiuid'conduits to said second pair of conduits or to each other. saidsecond valve comprising a cylinder, a piston rotatable in said cylinder,said piston having an internal passage extending longitudinally thereof,each end of said passage terminating in one of a pair of" generallyradial passages extending from said internal passage to spaced ports onthe exterior of said piston, said piston having a pair of recesses inits peripheral surface located substantially diametrically opposite saidports and extending circumferentially of said piston for less than halfof the periphery thereof, said cylinder having a first pair of portsspaced angularly and longitudinally the same as said piston ports andleading to said one pair of conduits so as to connect said conduits witheach other thru said internal passage when said piston is in a firstposition wherein said piston ports are aligned with said first pair ofcylinder ports, said cylinder also having a second pair of ports leadingto said second pair of conduits and located substantially that each ofsaid first pair of ports is connected thru its associated recess in saidpiston with one of said second pair of ports and said piston ports areblocked by the cylinder walls when said valve is rotated to a secondposition substantially' ninety degrees from said first position,andmeans for rotating said piston, said second 'valve being effective insaid first position to place said first valve in control of said motorand in said second position to cause collapse of one of said chambers bysaid spring. I

13. A fuel supply system foran internal combustion engine, comprisingfuel injector pump mechanism, means for varying the delivery of saidinjector pump mechanism, and hydraulic motor means for operatingsaiddelivery varying means including a pair of expansible chambers separatedby a movable wall,a first pair of fluid supply conduits connectedrespectively to said pair of chambers; control means for said motorincluding a source of motive fluid under pressure, a drain conduit, asecond pair of fluid conduits, a first control valve for selectivelyconnecting one of said second pair ofconduits to said source or to saiddrain conduit, and a second control valve for selectively connectingsaid first pair of fluid conduits to said second pair of conduits or toeach other, said second valve comprising a cylinder, a piston rotatablein said cylinder, said piston having an internal passage extendinglongitudinally thereof, each end of said passage terminating in one of apair of generally radial passages extending from said internal passageto spaced ports on the exterior of said piston, said piston having adiametrically opposite said first pair of ports, so

pair of recesses in its peripheral surface located substantiallydiametrically opposite said ports and extending circumierentially ofsaid piston for less than half of the periphery thereof, said cylinderhaving a first pair of ports spaced angularly and longitudinally thesame as said piston ports and leading to said one pair of conduits so asto connect said conduits with each other thru said internal passage whensaid piston is in a first position wherein said piston ports are alignedwith said first pair of cylinder ports, said cylinder also having asecond pair of ports leading to said second pair of conduits and locatedsubstantially diametrically opposite said first pair of ports, so thateach of said first pair of ports is connected thru its associated recessin said piston with one of said second pair of ports and said pistonports are blocked by the cylinder walls when said valve is rotated to asecond position substantially ninety degrees from said first position,and means for rotating said piston, said second valve being effective insaid first position to place said first valve in control of said motorand in said second position to terminate control of said motor by saidfirst valve.

l4. Afuel supply system for an internal combustion engine, comprisingfuel injector pump mechanism, means for varying the delivery of saidinjector pump mechanism, and hydraulic motor means for operating saiddelivery varying means including a pair of expansible chambers separatedby a movable wall, a spring biasing said wall in a pump deliverydecreasing direction, a first pair of fluid supply conduits connectedrespectively to said pair of chambers; control means for said motorincluding a source of motive fluid under pressure, a drain conduit, asecond pair of fluid conduits, a first control valve for selectivelyconnecting one of said second pair of conduits to said source or to saiddrain conduit, and a second control valve for selectively connectingsaid first pair of fluid conduits to said second pair of conduits or toeach other, said second valve comprising a cylinder, a piston rotatablein said cylinder, said pistonrhaving an internal passage extendinglongitudinally thereof, eachend of said passageterminating in one of apair of generally radial passages extending from said internal passageto spaced ports on the exterior of said piston, said piston having apair of recesses in its peripheral surface located substantiallydiametrically opposite said ports and extending circumferentially ofsaid piston for less than half of the periphery thereof, said cylinderhaving a first pair of ports spaced angularly and longitudinally thesame as said piston ports and leading, to said one pair of conduits soas to connect said conduits with each other thru said internal passagewhensaid piston is in a first position wherein said piston ports arealigned with said first pair of cylinder ports, said cylinder alsohaving a second pair of ports leading to said second pair of conduitsand located substantially diametrically opposite said first pair oi.ports, so

that each of said first pair of ports is connected thru its associatedrecess in said piston with one of said second pair of ports and saidpiston ports are blocked by the cylinderwalls when said valve is rotatedto a second position substantially ninety degrees from said firstposition, and means for rotating said piston, said second valve beingeffective in said first position to place said first valve in control ofsaid motor and in said second position to cause operation of saiddelivery varying mechanism to its minimum delivery position.

.15.. ,A .fuel supply system for .an internal cormbu'stion engine,comprising fuel injector pump mechanism, means for varying the deliveryof said injector pump mechanism, hydraulic motor meansfor-operating saiddelivery varying means including a pair of expansible chambers separatedby a movable wall and a connection between said wall and said deliveryvarying means, a spring biasing said wall in a delivery decreasingdirection, a main control valve for controlling the flow of motive fluidto said chambers so as to selectively move said wall in oppositedirections, a Joy-pass connection between said chambers, a second valvefor opening and closing said -by-pass connection, said second valvebeing effective when closed to place said first control valve in'controlof said motor means and when opened to permit operation of said wall tominimum delivery position by said spring regardless of the position ofsaid first control valve.

16. Hydraulic control apparatus comprising a fluid motor having a pairof expansible chambers separated by a movable wall, a spring biasingsaid wall in a direction to collapse one of said chambers, a first pairof fiuid supply conduits connected respectively to said pair ofchambers, a ,main control valve, connections between-said main controlvalve and said first pair of conduits, said main control valve beingeffective to control the flow of motivefluid from a source .of saidfluid under pressure to said. chambers, so as to selectively move saidwall in opposite directions; a by-pass connection between said.chamhers, a second valve for opening and closing said by-passconnection, said second valve beingefiective when closed to place saidfirst control valve in control of .said motor means and when opened topermit operation of said wall .to .one extreme position by said springregardless of the position of said first control valve. 7

17. A fuel supply system for an internal .combustion engine comprisingan air meter for measuring mass air flow to the engine, a fuel meter.for controlling fuel flow to said engine according to apredeterminedvalue of the fuelto-air ratio, a manually-operated mixture control insaid fuel meter including a system of metering jets and a rotatablemixture control valve effective to predetermine the fue1-to-air ratiobetween maximum and .minimum operating values, an injector pumpmechanism for delivering fuel to said engine and a passage for the flowof fuel thereto from said fuel meter, means in said mechanism to varythe rate of said fuel delivery, hydraulic motor means for positioningsaid delivery varying means in response to a motor fluid pressuredifferential supplied thereto, and spring means biasing said motor meansfor movement in a delivery decreasing direction; first means forcontrolling said motor means including a valve having a normal positionin which saidmotor means is stationary and effective upon oppositemovements-from said normal position to cause-operation of said motormeans in opposite directions, and means responsive to pressuredownstream from said fuel meter for operating said valve; second meansfor controlling said motor means, said second means comprising a motor,by-pass valve and means for operating said -by=pass valve between afirst position in which it by-passes said motor means and cuts oil? flowof motor fluid thereto and a second position in which said motor :meansis controlled solely by said first motor control means, a connectionbetween said means for operating said by-pass valve and saidmanually-operated mixture control, said motor by-pass valve beingeffective whensaid mixture control is operated to a motor cut-offposition to render said first means ineffective by :reducing said motorpressure differential to zero value, thereby allowing said spring meansto position said fuel delivery varying means for minimum delivery fromsaid pumps.

18. .A fuel supply system for an internal combustion engine, comprisinga first conduit for air flowing into said-engine for combustionpurposes, means in said first conduit effective to produce an airpressure differential that is a measure of the air flow; a secondconduit for fuel flowing into saidengine; .a metering orifice in saidsecond conduit, the .fuel pressure differential across said orificebeing a measure of the fuel flow therethru, and a fuel meter responsiveto said air pressure differential effective to vary said fuel pressuredifferential whereby said fuel flow is proportional to'said "airflow; amanually-operated mixture control for varying the area :of said orificeeffective to control the value of said proportionality .of fuel-to-air,an injector pump mechanism for delivering fuel to said engine, means insaid mechanism to vary the rated said fuel delivery, a passage for flowof fuel discharged from said imetering orifice to said injector pum-pmechanism, and hydraulic motor means for positioning said deliveryvarying means; first means controlling said motor means including -avalve having a normal position in which said motor means is stationaryand effective upon opposite movements from said normal position to causeoperation of said motor means :in opposite directions and meansresponsiVe to the metering orifice discharge pressure for operatingsaidvalve; and second means connected to said mixture control forcontrolling said motor means independently of said first means wherebywhen said mixture control is operated to a motor cut-01f position saidmotor actuates said fuel pump delivery varying means for minimumdelivery.

'MILTON E. CHANDLER.

